Simplify the following expression: $r = \dfrac{p}{6} + \dfrac{p}{8}$
Answer: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $6$ and $8$ $\lcm(6, 8) = 24$ $ r = \dfrac{4}{4} \cdot \dfrac{p}{6} + \dfrac{3}{3} \cdot \dfrac{p}{8} $ $r = \dfrac{4p}{24} + \dfrac{3p}{24}$ $r = \dfrac{4p +3p}{24}$ $r = \dfrac{7p}{24}$